In a dynamic analysis involving a rotating structure, the program takes inertia effects due to the rotational velocity into account. These effects are nonlinear and are automatically included in a nonlinear transient analysis (NLGEOM,ON).

Depending on the model, these effects may be linearized either in a rotating reference frame or in a stationary reference frame. The latter is commonly used in rotordynamics analysis and is the scope of the Rotordynamic Analysis Guide. This section addresses differences between the two approaches as well as rotating reference frame dynamics.

The linearization and reference frame setting is driven by the CORIOLIS command. When activated, linear dynamics analysis (such as modal or harmonic analysis) of a rotating structure can be performed.

For additional information on the equations, see Rotating Structures in the Theory Reference.